1. Field of the Invention
The present invention relates to a fiber stock preparation system for preparing a fiber suspension for use in a paper-making machine, and, more particularly, to an apparatus for discharging a pressurized fluid from a pressurized vessel in such a fiber stock preparation system.
2. Description of the Related Art
A fiber stock preparation system is used to prepare fiber stock or a fiber suspension which is used in a paper-making machine for the production of a fiber web. To provide a finished fiber web with certain physical characteristics, it is known to load the fibers in the fiber stock with a chemical compound. For example, it is known to load the fibers in a fiber stock with calcium carbonate using a pressurized vessel. For the details of such a fiber loading system, reference is hereby made to U.S. patent application Ser. No. 09/130,176, entitled "APPARATUS AND METHOD FOR CHEMICALLY LOADING FIBERS IN A FIBER SUSPENSION", filed Aug. 6, 1998, which is incorporated herein by reference.
In a fiber loading system as described above, the pressurized vessel must be maintained in a pressurized state to effect proper loading of the fibers in the fiber stock. Nonetheless, the pressurized vessel is typically discharged to a transport system such as a conveyor or auger which is in communication with ambient atmospheric pressure. Thus, it is necessary to maintain the interior of the pressurized vessel at a relatively high pressure while at the same time allowing the loaded fiber stock to be discharged to an ambient pressure.
What is needed in the art is an apparatus which maintains a pressurized vessel in a fiber stock preparation system at a higher pressure while allowing the fiber stock to be discharged to ambient pressure.
What is further needed in the art is an apparatus for discharging a pressurized vessel in a fiber stock preparation system which has an adequate flow rate to supply a loaded fiber stock to a paper-making machine, and is simple and relatively inexpensive to manufacture.